>I want to change the color of GridLines from light blue(default valve) to white.
>I tried a command "Show[%, DefaultColor -> RGB[1,1,1]] " and found it only
>
>changes the color of frame and axes. Any help will be appreciated.
If you want to change the style of GridLines you can do this by
specifying the GridLines explicitly.
Show[
Graphics[ Circle[ {-1,-1}, {2,1}]],
GridLines ->
{Table[ {x,{GrayLevel[0], Dashing[{0.01}]}}, {x,-3,1,.5}],None}]
You have to put down their positions as well as their style
so this may not be convenient.
Tom Wickham-Jones
WRI